"When we did Borderlands, we stuck our neck out pretty far," he said. "We did what was seen as a bizarre blending of genres, a bizarre art style and a bizarre sense of humor.

"People loved the game and rewarded us by purchasing the game. We didn't just want to do a wimpy sequel. We wanted to do a full, ambitious, giant sequel, and part of that is the new feeling of experience, and that happens with new character classes."

Gibson continued by explaining how the new classes mix up the gameplay.

"If we did the exact same guy but just a new environment, how new does that feel? Even the one class that is similar - the Commando - you could point that to the Soldier but the way that works and his entire treatment is nearly entirely different.

"The only similarity is that he has a turret. But this turret now is upgradable and this turret can now be deployed as multiple turrets. This turret can be mounted on walls and ceilings. It's a much different experience.

"He's not even the healer so much as the Siren is the healer this time. We wanted everything to feel new as much as it can."

Borderlands 2 will be available for Xbox 360, PlayStation 3 and PC in September 2012.